JP2000128999A - Master batch pellet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a master batch pellet in which a fine inorganic filler is densely packed. SOLUTION: This master batch pellet is obtained by packing an inorganic filler having 2-7 μm average particle diameter whose surface is subjected to hydrophobicizing treatment in a packing amount of 200-900 pts.wt. based on 100 pts.wt. polyolefin-based resin into the polyolefin-based resin, and a ratio (M-MFR/B-MFR) of melt flow rate (M-MFR) of the polyolefin-based resin to melt flow rate (B-MFR) of diluting pellet used for dilution is >1 and <4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to highly filled fine inorganic fillers, and to pellets used for dilution, to impart good dispersibility of the inorganic fillers and mechanical strength to a product obtained by molding after blending. Regarding master batch pellets that can be made.

[0002]

2. Description of the Related Art Polyolefin resin compositions containing inorganic fillers are widely used in various industrial parts and the like because of their good rigidity and heat resistance.

[0003] In particular, polyolefin resin compositions filled with talc can be provided with thermal and mechanical properties such as heat resistance, rigidity and creep resistance, and are therefore used in large quantities, mainly in the field of automobiles.

In general, the above composition is prepared by mixing a polyolefin resin with an inorganic filler, and then kneading and kneading the mixture with a single-screw or twin-screw extruder to form pellets.

However, in recent years, for the purpose of reducing product cost, a master batch pellet made of polyolefin resin in which a powdery inorganic filler is filled into a polyolefin resin at a higher concentration than the intended concentration is used, and the inorganic filler is not included. After blending with pellets (hereinafter, referred to as “diluted pellets”) used for dilution made of a polyolefin-based resin, a method of directly molding with an injection molding machine, an extrusion molding machine, or the like is adopted.

On the other hand, the rigidity and impact resistance of the resin composition filled with the above-mentioned inorganic filler strongly depend on the particle diameter of the inorganic filler. Many compositions containing a filler have been disclosed.

[0007]

However, after blending masterbatch pellets and diluted pellets highly filled with an inorganic filler having a small particle size, a product obtained by molding has poor appearance due to poor dispersion of the inorganic filler. They tend to occur easily and have low mechanical strength.

This tendency often becomes a problem in the field of injection molding in which high fluidity of the diluted pellets is required, and there is a limit to molding applications using the diluted pellets and the master batch pellets.

Therefore, a master batch pellet highly filled with a fine inorganic filler capable of imparting good dispersibility of the inorganic filler and mechanical strength to a product obtained by blending and molding with the diluted pellet is conventionally proposed. Has not been reached.

[0010]

Means for Solving the Problems The present inventor has conducted intensive studies in order to achieve the above object, and as a result, the melt flow rate (MFR) of the polyolefin resin constituting the masterbatch pellet has been reduced to the MFR of the diluted pellet. By adjusting to a specific range to solve the above problem,
The present inventors have found that a masterbatch pellet capable of imparting good dispersibility and mechanical strength of an inorganic filler can be obtained, thereby completing the present invention.

That is, the present invention relates to a polyolefin resin 1
The polyolefin-based resin has a melt flow rate (M-MF) of 200 to 900 parts by weight based on 100 parts by weight of an inorganic filler having an average particle diameter of 2 to 7 μm.
R) is relative to the melt flow rate (B-MFR) of pellets made of polyolefin resin used for dilution,
It is a masterbatch pellet characterized by the following relationship.

1 <[M-MFR] / [B-MFR] <4

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As the polyolefin resin used for the masterbatch pellets of the present invention, known resins can be used without any limitation. Specifically, homopolymers of α-olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, etc., and blocks or random copolymers of the above α-olefins Or a mixture of these homopolymers or copolymers. The above α-
Specific examples of the block or random copolymer of olefins include an ethylene-propylene random copolymer or an ethylene-propylene block copolymer having an ethylene content of 10% by weight or less, and an ethylene content of 10% by weight or less.
Weight% or less of ethylene-butene-1 random copolymer and ethylene-butene-1 block copolymer.

In the present invention, among the above polyolefin resins, a propylene resin is preferable, and particularly, an ethylene-propylene block copolymer is most preferably used.

Although the above polyolefin-based resin can be used for the diluted pellet in the present invention without any limitation, it is preferable to use a propylene-based resin. If necessary, ethylene-propylene rubber (EPR), ethylene-butene rubber (EBR), ethylene-hexene rubber (EHR),
Olefin elastomers such as ethylene / octene rubber (EOR), styrene / ethylene / butylene / styrene rubber (SEBS), styrene / ethylene / propylene /
A styrene elastomer such as styrene rubber (SEPS) can be blended.

The MFR of the diluted pellet of the present invention is appropriately determined according to the use of the obtained molded article, required physical properties, and the like, and is not particularly limited.
° C, 2,16 kg load) is 15 to 50 g / 10 min, preferably 18 to 45 g / 10 min, more preferably 20 to 50 g / 10 min.
40 g / 10 min is common. That is, the MFR is 15 g
When the rate is less than / min, not only is it difficult to mold a large molded product, but the resulting molded article tends to have poor appearance such as a flow mark. In addition, the MFR is 50 g / 10
If the amount exceeds the above range, dispersion of the master batch pellets of the present invention in diluted pellets tends to be difficult, and the resulting molded article may have poor appearance.

Next, as the inorganic filler used in the present invention, a known inorganic filler used as a modifier for polyolefin or the like can be used without any limitation. Specific examples include talc, calcium carbonate, barium sulfate, zinc sulfide, calcium oxide, magnesium hydroxide, and mica. Above all, talc has a high effect of imparting thermal and mechanical properties such as heat resistance, rigidity and creep resistance, and can be suitably used.

The average particle size of the inorganic filler in the present invention is 2 to 7 μm, more preferably 3 to 6 μm. When the average particle size is less than 2 μm, the bulk specific gravity is small, handling is extremely difficult, and the cost increases. On the other hand, if the average particle size exceeds 7 μm, the mechanical properties such as the rigidity and impact resistance of the molded product obtained from the master batch pellet and the diluted pellet are remarkably reduced, which is not preferable.

The average particle diameter is a particle diameter at a cumulative amount of 50% by weight measured by a laser diffraction scattering method.

In the present invention, in order to improve the dispersibility of the inorganic filler in the resin, various inorganic titanate-based coupling agents, organic silane-based coupling agents, polysiloxane compounds, various surfactants, various silane compounds, The surface is preferably hydrophobized with a hydrophobizing agent such as metal soap, higher alcohol, fatty acid, fatty acid metal salt, or fatty acid ester. Among the treating agents, an organic silane coupling agent and a siloxane compound are preferred, and a polysiloxane compound modified with a silazane compound is most preferred.

The amount of the surface treatment agent to be treated is the same as the amount of the inorganic filler 1
The amount is preferably 0.2 to 5 parts by weight, and more preferably 0.2 to 5 parts by weight.
More preferably, 3 to 3 parts by weight, most preferably 0.4 to 2 parts by weight. The surface treatment of the inorganic filler can be performed by a known method, that is, a dry method or a wet method.
Specifically, the surface treatment agent is directly sprayed on the inorganic filler obtained by pulverization or synthesis, or a dry method in which the treatment is performed by dry blending, the inorganic filler and the treatment agent in a solvent such as water at room temperature or A wet method of stirring and treating under heating is used.

In the masterbatch pellets of the present invention, the compounding amount of the inorganic filler is 1
200 to 900 parts by weight with respect to 00 parts by weight,
It is preferably from 50 to 500 parts by weight. If the amount of the inorganic filler is less than 200 parts by weight, the effects of the application of the present invention are small, and the economic effect is also small. On the other hand, when the amount is more than 900 parts by weight, the amount of the polyolefin resin is too small, and it is difficult to granulate the pellets.

The master batch pellets of the present invention are prepared by mixing the polyolefin resin constituting the master batch pellets with the MFR (M-MF).
R) is the ratio (M-MFR / B-MFR) to the MFR (B-MFR) of the diluted pellet, and must be more than 1 and less than 4, as shown in the above formula, and is 1.4 or more. More preferably, it is less than 3.

That is, the MFR of the diluted pellet and the MFR of the polyolefin resin constituting the master batch pellet
When the ratio is out of the above range, poor dispersion of the inorganic filler occurs in a molded product obtained from the master batch pellets and the diluted pellets, so that the object of the present invention cannot be achieved.

Further, the average particle diameter (D) of the inorganic filler forming the masterbatch and the polyolefin resin 1
Masterbatch pellets satisfying the following expression in relation to the inorganic filler amount (W) parts by weight to 00 parts by weight and the MFR (B-MFR) g / 10 min of the diluted pellets have the better dispersibility of the inorganic filler. Therefore, it can be used suitably and is preferable. In particular, the value calculated from the following relational expression is more preferably 0.7 or more, and most preferably 0.8 or more.

100 × D / (W × log [B-MFR]) ≧ 0.6 In addition to the inorganic filler, the masterbatch pellets of the present invention need to be in a range that does not significantly impair the effects of the present invention. A known compounding agent can be added accordingly. For example, examples of the compounding agent include organic fillers such as wood flour, rice husk flour, bamboo flour, coconut husk flour, various cereal flours, and cellulose flour. In addition, phenol-based, organic phosphite-based, phosphite-based organic phosphorus-based, thioether-based antioxidants, hindered amine-based heat stabilizers, benzophenone-based, benzotriazole-based, benzoate-based ultraviolet absorbers, nonionic-based , Cationic, anionic antistatic agents, bisamide-based, wax-based, organometallic salt-based, ester-based lubricants, oxide-based, hydrotalcite-based decomposing agents, hydrazine-based, amine-based metal-inactive, etc. Agent,
Flame retardants such as brominated organic, phosphoric acid, antimony trioxide, magnesium hydroxide, and red phosphorus, inorganic and organic antibacterial agents such as metal ion, inorganic and organic pigments, nucleating agents, plasticizers, foaming agents, etc. It is also possible to mix known additives in an auxiliary manner.

The size of the masterbatch pellets of the present invention may be in a known range without any particular limitation. Generally, a pellet having an equivalent diameter of 2 to 10 mm is suitable.

In the present invention, various methods can be applied for producing master batch pellets, and the production method is not particularly limited, but the following method is preferable.

That is, when the polyolefin resin and the inorganic filler are stirred at a high speed at a high temperature by a mixer having stirring blades therein, when the polyolefin resin starts to melt,
That is, a method in which the load current of the stirring blade starts to largely shake and reaches a predetermined load current or more, the mixture is taken out, and then the mixture is supplied to an extruder to be pelletized.

In the present invention, the mixing ratio of the masterbatch pellets and the diluted pellets is not limited at all, and may be appropriately determined so as to have a desired mixing ratio. The blending amount of the pellets is preferably 2% by weight to 60% by weight, and more preferably 5% by weight to 50% by weight.

When the amount of the masterbatch is 2 wt% or less, there is almost no effect of improving the mechanical properties.
Conversely, if the content exceeds 50 wt%, the moldability is poor, which is not preferable. In addition, mixing of the diluted pellets and the master batch pellets is performed by using a known mixing device, for example, a high-speed mixer, a tumbler, a ribbon mixer, a Henschel mixer, or the like at a mixing ratio according to the purpose, and then, extrusion molding. It is preferable that the raw material mixture is directly charged into a molding machine such as an injection molding machine or an injection molding machine and melt-mixed.

[0032]

The masterbatch pellets of the present invention are highly filled with a fine inorganic filler, which has been difficult to disperse into diluted pellets, so that the cost of transporting such a composition can be reduced. Not only is possible, but the mechanical properties of the polyolefin-based resin composition blended with the masterbatch pellets and the diluted pellets of the present invention are almost equivalent to those in the case where the inorganic filler is directly blended with the polyolefin resin. .

The polyolefin-based resin composition obtained by blending the masterbatch pellets of the present invention with diluted pellets can provide molded products having good surface appearance and dimensional accuracy, and can be used for various industrial products such as automobile parts. Can be suitably used.

[0034]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In addition, the raw material in an Example is as follows.

(1) Polyolefin resin A-1: Melt flow rate (MFR) is 10 g / 10
Minute (230 ° C.) propylene-ethylene block copolymer (trade name: Tokuyama Polypro MS650) A-2: Melt flow rate (MFR) is 21 g / 10
Minute (230 ° C.) propylene-ethylene block copolymer (trade name: Tokuyama Polypro MS670) A-3: Melt flow rate (MFR) is 30 g / 10
Minutes (230 ° C.) propylene-ethylene block copolymer (trade name: Tokuyama Polypro MS680) A-4: Melt flow rate (MFR) is 45 g / 10
(230 ° C.) propylene-ethylene block copolymer (trade name: Tokuyama Polypro JW792H) (2) Inorganic filler B-1: Surface-treated with silazane-modified polysiloxane (processed / processed amount by dry method; 0.8 wt%) Talc having an average particle size of 3.7 μm (Talc manufactured by Asada Flour Milling Co., Ltd. (trade name: M
B-2) Surface-treated with γ-aminopropyltriethoxysilane (processing by spraying a processing agent after pulverization, processing amount: 0.7 wt%) Average particle size 3.7 μm Talc (as processed by talc (trade name: MMR) manufactured by Asada Flour Milling Co.) B-3: Surface-treated with silazane-modified polysiloxane (processed by spraying a processing agent after pulverization; (8 wt%) talc having an average particle size of 6.0 μm (a talc (trade name: JA13R) manufactured by Asada Flour Milling Co., Ltd.) The results of the examples were measured and evaluated by the following methods.

(A) Dispersibility of inorganic filler Diluted pellets and masterbatch pellets are blended at a predetermined ratio, and are directly injected into an injection molding machine to form a flat plate having a thickness of 2 mm, and visually disperse the inorganic filler. The sex was evaluated.
The relation between the molding conditions and the symbols related to the filler dispersibility in the table and the dispersibility of the inorganic filler are as follows.

(Molding conditions) Injection molding machine; J150SSIIA manufactured by Nippon Steel Works Molding temperature; 190 ° C Mold temperature; 40 ° C Back pressure; 0.1 MPa (Evaluation of dispersibility) Was determined.

A: No poor dispersion was observed.

…: Thin and undispersed talc can be confirmed.

Δ: Marble-like poor dispersion is developed.

X: Marble-like dispersion failure is strongly exhibited.

(B) Flexural modulus Measured according to JIS K7203.

(C) Izod impact value Measured according to JIS K7110.

(D) Heat deformation temperature Measured in accordance with JIS K7207 (load: 0.45 MPa).

Examples 1 to 8 A supermixer (SMV-10 manufactured by Kawada Seisakusho) was prepared by heating the above-mentioned polyolefin and the inorganic powder filler at a predetermined mixing ratio (parts by weight) shown in Table 1 at 130 ° C.
0) and stirred and mixed at 1300 rpm. The temperature was raised to 175 ° C. by the heat transfer and stirring heat, the polyolefin resin began to melt, and when the load current of the rotating blades fluctuated by 300%, the discharge valve was opened and the lower cooling mixer (SMC100N manufactured by Kawada Seisakusho) To 300 rpm
And cooled. After cooling, the mixture was charged into a 50 mmφ extruder manufactured by Ishinaka Tekko to prepare master batch pellets.

The master batch pellets and the diluted pellets were blended at the mixing ratio (weight ratio) shown in the table, and directly injection molded to prepare a flat plate for evaluating dispersibility and a test piece for measuring physical properties. Then, the dispersibility and physical properties of the inorganic filler were evaluated using the prepared test pieces.

The results are shown in Table 1.

[0048]

[Table 1]

Comparative Examples 1 to 4 The above-mentioned polyolefin and inorganic filler were supplied to a supermixer (SMV-100 manufactured by Kawada Seisakusho) heated at 130 ° C. at a predetermined mixing ratio (all parts by weight) shown in Table 2. And mixed with stirring at 1300 rpm. The temperature was raised to 175 ° C. by heat transfer and stirring heat, the polyolefin-based resin began to melt, and when the load current of the rotating blades fluctuated by 300%, the discharge valve was opened and the cooling mixer (SMC100N manufactured by Kawada Seisakusho) underneath. Transferred and cooled at 300 rpm. After cooling, the mixture was charged into a 50 mmφ extruder manufactured by Ishinaka Tekko to produce masterbatch pellets.
The dispersibility and physical properties of the inorganic filler were evaluated in the same manner as described above.

The results are also shown in Table 2.

Comparative Example 5 The production of masterbatch pellets was attempted in the same manner as in Example 1 except that the above-mentioned polyolefin, fibrous inorganic filler, and powdery inorganic filler were mixed at a predetermined mixing ratio shown in Table 2. could not.

[0052]

[Table 2]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B29K 23:00 105: 16 F term (Reference) 4F070 AA13 AA14 AA15 AA16 AB08 AC14 AC16 AC20 AC27 AD06 AE01 FA04 FB04 4F201 AA09 AB11 AB16 AB28 AC08 AH17 AR17 BA02 BC12 BC19 BC37 BK15 BL08 BL43 4J002 AB015 BB031 BB051 BB121 BB151 BB161 BP021 DE076 DE086 DE236 DG026 DG046 DJ046 DJ056 FD016 FD020 FD040 FD070 FD100 FD070 FD070 FD070 FD070 FD070 FD070 FD070 FD100

Claims (3)

[Claims] 1. An inorganic filler having an average particle size of 2 to 7 μm is added to a polyolefin resin in an amount of 200 to 90 parts by weight based on 100 parts by weight of the polyolefin resin.
0 parts by weight, and the melt flow rate (M-MFR) of the polyolefin-based resin is as follows with respect to the melt flow rate (B-MFR) of the pellet made of the polyolefin resin used for dilution. Master batch pellets characterized by being related. 1 <[M-MFR] / [B-MFR] <4 2. The pellet used for dilution has an MFR of 15
The masterbatch pellet according to claim 1, wherein the weight is from 50 g / 10 min. 3. An average particle diameter (D) of the inorganic filler to be filled in the master batch pellets, an inorganic filler amount (W) parts by weight based on 100 parts by weight of the polyolefin resin, and a melt flow rate of pellets used for dilution. (B-MFR)
The relationship with g / 10 min is (D / (W × log [B-MFR])) × 100 ≧
2. The masterbatch pellet according to claim 1, satisfying 0.6.